Ring spinning machines ordinarily include many processing lines in which the textile fibers to be spun are drafted and twisted into yarns or the like. These lines are arranged side by side and terminate in vertical cops on which the yarns are wound as they are spun. A reciprocating ring rail in the vicinity of the cops causes the yarns to traverse up and down as they are wound onto the cops to fill out the yarn packages in the desired manner.
Service robots sometimes are associated with such ring spinning machines to carry out various service functions at the several processing lines. Typically, a service robot will be movable along the length of the ring rail to the location of a processing line to be serviced and includes a vertically movable carriage for one or more working heads. After the robot has been positioned at the desired processing line, the vertical position of the carriage is correlated with the vertical position of the work to be done and the working head is extended horizontally as necessary to accomplish the task for which it was designed.
In some instances it is desirable to move the carriage of a service robot into a desired positional relationship with respect to the reciprocating ring rail and hold it there while a working head is carrying out its task at the adjacent processing line.
Systems known to coordinate the movements of different independently driven machine parts, for instance according to DE-AS 25 01 338, are not quite suitable for use in modern spinning frames since they are designed for slower sequences of movement and since they do not achieve the necessary accuracy in the coordination of the said movements.